Wet-ore belt stratifier



March 4, 1958 R. HACKNEY ETAL 2,825,462

v WET-ORE BELT STRATIFIER Filed Feb. 20, 1956 2 Sheets-Sheet 1 incense/J R. HACKNEY TAL T-ORE BELT March 4, 1958 STRATIFIER 2 Sheets-Sheet 2 Filed Feb; 20, 1956 Unite This invention relates generally to wet-ore concentrators of the type in which a slurry of finely divided ore and water is flowed downwardly over an incline surface of an upwardly moving belt, and more particularly the invention relates to such a concentrator in which the consistency of the downflowing slurry is carefully controlled by providing separate channels and sources of auxiliary water for slurry from each part of the slurry hopper, and in which turbulence is promoted in the downowing stream by means of closely spaced oblique balles on the surface of said belt. Some of said baiiles are inclined to the left and some to the right, the two kinds intersecting to present a succession of diamond shaped pockets in the path of the downtiowing stream of water and ore.

In many types of mining, particularly in gold mining, the desired mineral is intimately associated with rock in the ore, and it is necessary to separate the two by grinding the ore to tine granules and then subjecting the powdered mixture `to some means of separation. A cornmon means of doing7 this, particularly successful in gold mining, is the wet-ore concentrator. The pulverized ore is mixed in a slurry and passed downwardly over an inclined bed, which may be immovable, but is preferably an endless belt continuously moving upwardly countercurrent to the ow of the mixture of water and granulated ore. It has been found desirable to supplement the water in the slurry with additional water deposited on the inclined surface at a point upstream from the point at which the slurry is fed onto the surface. The relatively light particles of rock -are entrained in the downilowing water and carried to the downstream end of the inclined surface where they are discharged as waste tailings to a dump. The relatively heavy particles of valuable mineral tend to be precipitated out of the downowing stream and to remain on the inclined surface, moving with it to the upstream end of the incline.

In the past, a substantial percentage of valuable mineral is carried down with the tailings and lost. With the improvement in wet-ore concennators in recent years, it has become more and more profitable to rework tailings from old mines, or to work ores which were hitherto believed to be too poor to provide an economic recovery. One such improvement has been to cover the llexible belt with a liexible wire mat adapted to introduce turbulence in the downflowing slurry and thereby insure more effective and intimate washing. These wire mats have been subject to the objection however that their movement with the belt tended to subject the belt to such Wearing and cutting that it was eventually destroyed, and also to the objection that the wire mats, even if coated, readily succumb to rust and corrosion.

Previously known ore belts have also been subject to the objection that they were relatively ineffectual in trapping tine grains of valuable metals but tended to snag twigs and leaves and other waste materials sometimes present in the slurry.

It has usually been the practice to discharge the granulated ore onto the inclined surface at a point a shortrates Patent distance downstream from the upper end, and to supply enough water at the upstream end to wash all the tailings to the lower end. However, the eiliciency of separation of light and heavy particles has not been uniform at all points across the bed from one side to the other. If suilicient water was provided at the sides to achieve adequate Washing in those locations, too many metal particles were carried away with the tailings from the center portion. was regulated to achieve most eective washing in the center, the lateral portions -of the upwardly moving belt could not be used with maximum eiciency lest they begin to accumulate ore and carry it to the upper end of the incline without separation.

lt is a major object of the present invention to provide a wet-ore concentrator in which the inclined ore bed is divided into a plurality of relatively narrow parallel channels each of which is supplied with a slurry of ore and water from a different part of the slurry hopper and above the upstream part of the inclined ore bed.

lt is a further object of this invention to provide separate adjustable water taps for each of said channels so that the auxiliary water introduced at the upstream end of each channel may be exactly that required to complement the proportions of water and ore in the slurry supplied to that particular channel from the part of the slurry hopper with which it is in communication.

It is another object of this invention to provide a wet-` ore concentrator in which the downilowing stream of finely divided ore entrained in water is passed over a continuous series of turbulence-inducing batlles which are molded integrally with the ore belt and are constructed of the same rubber-like material.

it is a still further object of this invention to provide ore belt bales of a novel pattern, in which all the baffles; are disposed obliquely to the direction of a belt travel,

some bal'lles inclined to the left and some inclined to the right, and the right and left baiiles intersecting eachV a specific embodiment of the invention illustrated in the accompanying drawings, in which:

Figure 1 is a perspective View of a wet-ore concentrator constructed in accordance with this invention;

Figure 2 is a vertical sectional view taken transversely through the slurry hopper part of the concentrator as viewed upstream in the direction of the arrows 2 2 in Figure l;

Figure 3 is a plan view of the fragment of a horizontal section through the concentrate recovery hopper as indicated by the arrows 3-3 in Figure 1;

Figure 4 is a plan View of an ore belt constructed ac-k cording to the present invention and comprising a part of the apparatus illustrated in Figures 1 to 3; and

Figure 5 is a perspective view of an enlarged fragment of the belt of Figure 4 as it is seen from the vertical section taken in the direction of the arrows 5 5 in Figure 4.

In Figure 1 a wet-ore concentrator apparatus, indicated generally by the numeral 10 is supported in a framework 11 comprised of a bolted or welded metal structure. The upper part of framework 11 consists of a pair of angle irons 12 and 13 (the latter is visible in VPatented Mar. 4, 1958,A

On the other hand, if the downowing stream f FigureZjbut notinFigure`1')"which are inclined to ground level" and-carryv cross members 14- and 15: Y

Supported on cross members 14 and 15 are a plurality of/parallel channels, 16, k17, 185 19,420, and 21.

dolwnstreamiends respectively,` fsaidI shafts beingL provided"` with pulleys124 and" 25," respectively:

'endless beltSZ 27.3233V 29; 30',`

of rubber.; o r other resilientYY rubber-like materialLV arel mountedon pulleys 2j4ia'11d25Y withA their upper spans audi. 311i, Vruatlef` Upstream from slurry conduits 58 to 63',`auxiliary water isflowed toeachrof-Y- thebelts-26- to 31`- byfmeansof an" auxiliary water pipeline 64 which is provided with'A sepai rately adjustable taps 65 to170,onefor each of the belts seate'df. in'f*channels16;;17;V 18', 119;. 20; and' 21 respecv tivelygjtlre` lower `spanY of the belts beingjY carried Yunder Y infaiclockwisej direction;` as' viewed in Figure* 1,1 withV the' upper'belt surfaces moving; up Vthe inclineas indicatedV byv the varrowZ, Iby means fof a motor- 33,"mounted'on` armotorrplatform `34 ,suspendedby frame members `35 ungle'n'theLup'per end ofthe inclined'v frame members `12` and 13. The-'motor 33drives a speed..reductior'1` gear box'36. the outputfsprocketY 37 of whichrrotates sprocket 38'on shaft122 'by means ofachaing. Orel to be p rocessed in. the wet-ore separator 10. must be lirst reduced'.

to'a;finelydividedlgranulated` form usually by crushingv The granulated ore may be conveniently.. Yfed .from the'. ball'v millU and 'grinding'y in a ball mill (not shown).

0 1-storagehopper 40' through.. a conduit. 41..,by means of.: a screw conveyor 42,. through. outlet. 43,'.-to.;a V.sll'lrrry hopperV 44,' supported on. angle irons.12 and :13. by suppprts. 44ml; Screw conveyor. 42'. maybe. Vconveniently drivenby. means `oa .shaftxlV connected to power not shown, andtova gear box.46:mountedat.the end; ofthescrew'.l conveyor.Y Preferably, movementrof. the YfinelyV dividedore. through conduit..4r1fis facilitated bythe iu-Y ti'oduction of'water into the conduitby way of. line 47. Above thev slurry hopper 44,1`a. slurry water. supply pipe.` 48;. positioned transversely with respectto the. Wetore concentratorzlt). dischargeskslurry water intotheslurry hopper. 44.at points distributedLfromone'sideofthe concentratortothe.other;`v l Y Y Y Thefslurrywithing'slurry hopper. 4er/.55..Snedv to a,

fairly'uniform consistency by means of. an .agitator 49,-

which consistsof a shaft. 50,. journaled. at its right' and left zendsfin.. pillowv Vboxes 51 and 52 on. the right and left sides, respectively, of the concentrator 10. Thesh'aft- 50.is,pr0vided with.a sleeve 53'carrying; radial stim'ng rod'sf5`4.. Agitator. 49is drivengby.' means of a'. driving pulley 55 mountedjon the. Iightend of the-upstreamiore Vbelt shaft 22, a driven pulley 56.v mounted-on agitator shafti50, and abelt. 57 between pulley/s55 and 56..v

. The bottom. of'` slurry hopper 44is providedfwithfa plurality of' funnel-shaped-outlet conduits` 531e 63,V whichV are disposed in a -IinetranSVerse 'to' the?.moving-beltsv 26. to. 31.. Althoughthe slurry. zwithinYV slurrf'yjlhopper' 44 is stirred tofairly uniformiconsisteneyyby the; actionof the vagitator 49,` it isfinevitableY in an' apparatus oipracticaldimensionsthat there will be. some variation in; conv. sisteney Vand .densityof slurry.A frorrrpoiutl to* point along the lengthof'slurry hopper 44. It isV quite4 likely/@tiratiV thesluny descending throughconduitsf 60 and 61. to center belts. 28 and. 29k willhave a lower percentageV of water and therefore greater n density than. the. slurry ude-v scending through` the side outlets 53 and-63 to side belts 2 6 and' 31'..

In order to orderto achieve most effective separation:vof'metalfrOm ore. fora given volume 'of ore a handled per'Y hour.' slurry fomfeach partof slurry Yhopper 44-'i'sfvc'onh`nedfto itsown sIuice channell and to the belt onwhich it is initiallyv de? posited, and .the .amount ofauxiliary wastewater...V intro- Vducedronto the. belts ata pointupstreamjfrom thefslurryVV condu1ts-58to 6? by means to be-describedrhereinaftenj adjustedinowrate for eachfof the.; belts is.H separately 26lto` 31.

adjust washing` conditions onY each. beltriu.Y

` tairrmrigures ands.. Taegb'elt is made mansarda@ Y 26 to 31.

Auxiliary water fromtaps to-70 ows toV the upstream ends of belts 26 tof31 via troughs 71 Vto 76'.

As slurry from conduitsY 58 to A63V is Ydeposited 'on'V theY belts26 Vto 31, it tends toibeicarr'ied up'the incline by dump.

The` valuable particles of metal, however, whichl are much heavier than therock particles are precipitated fromv tlietdiwvnllowiug` suspensionjon'to the surface of "the belt, f and*"entrapped thereonVV by 'means of af'baie arra"rigeuient.

to be'd'e'scribedin" connection with Figuresct and v5; and

YVcarriedoverthe'upstream pulley'124. Y As the/belt isinvertedin itsniovement V.along the' lowerrreturn span; lthe i.Y

accumulated metal particles4 aredumpedl into a on'ce'nz-Y 'Y trate; trougl'1178.V a Y Y Y The concentrateis washedfrom thetbales by means of concentrate' wa'sh` sprays. 79 discharged from Openings' 80" disposedalon'g a concentrate washV pipeV S1 rwhirch is supportedltransvers'ely to Vore"corrcentrator 10 under the downwardly moving invert'edbelt'surfaces;

The recovered" concentrate' is' washed downwardlyV in Y concentrate recovery" chute 78 toa concentrate'bin'zgs which may conveniently, be mountedon casters' 83'1to r facilitate replacement of a lille'jd bin with an'` empty one.

Waterrescapes from the bin 82";as`the concentrate settles il therein. by`wayA of an. outl`et84,"` which, as seen from thev` broken away pfortioncrif the corner of bin'ZY in Figure l, and also-the plan view, ofFigure 3; is shielded' by means concentrate gradually lls Vup vbiirSZv t The construction;V of thebelts 2'6 to 3f is `shownin derubberfor`otherrrubberlike material, which is vsufficiently flexible. t. pass-.faround'fthe pulle'ys, and Yhas the tough resilient. `qualities off rubbenwlicli. assist in resisting, ero.-Y 'sionor other.V deterioration ,as Va result of'constant Vexposure toa .watersuspension offnely divided rockrand metal.

Preferably/,.thedb'elt is madefin .sections a few kfeetin Y lengtlrwlicliY maybe vul'cani'zedltogetter to make an end Y Y less .beltoffanytdesined length.. or may be used .to ,replaceA adarnagedlsection.ofatusedbeltl VThe belt isfin the form of. a channeltwitli vertical side walls .Sliffand'f 87 ,y between which diagonalVVA bale's sucli as .baTeS andfbafe .89 are: formedfextendingacross thelfeltV Vfrom Yside wall'. 8'6` to'sid'efwallSZ and'intersectingone anotherat 9.02"'. SicfY cessive belt..sectionsarle. .vulganized.togetherbyY means?v ol=overlapping ,tollglles.at their ends as .indicated at.9 1Y Y andseenmostclearly in :the sectional portion. of.` the'V perspectiveview oEigur-e. 5l.

. VThe-intersecting ba1=lies..x assise;V and. sa. may .be

classiedaaccording;,to..thei.r.. direction.` of inclination.` asV right'. flow. bellies.sggwhichtincline.obliquely across ythe belt. .26 with.. 'the right. enddownstream. fromlthe left end 92aQdistancetwhichintlieparticular embodiment shown, .l

is aboutzthree ltim'esJtlie:space.between successive baffles.

Right. `flowl .battles :tend.todivertl.ciownflowingy liquids-solid suspension` to .the The left.V flow balies, suchl as 1 baffle 89', are positioned obliquely across the downflo'wing stream-with..the left enda 973e'correspondingdistance downstream. from, the right-end.. 94; Left .flow battles .tend to.,impart. a. leftward. component` to the liquid-solids mixture flowingdown over the.be1t. v

As seen in the plan view of FigureL-, the .intersecting right. and..-left llow -baes presenta diamond. lpattern-fof pockets several pocketsr wide and-endlessly` succeeding' one another along the length of the belt, except at 91, where two sections are connected. The suspension of ore particles entrained in water is passed down over the upwardly moving belt 26 in a shallow stream confined between the side walls 86 and 87 and not much'deeper than the height of the bales 88 and 89. The bailles promote turbulence in the stream, causing the suspended particles' to be repeatedly shaken and sorted according to density as they are momentarily picked up or deposited in the circulatory currents which eddy about the baille surfaces, as indicated by the current ilow arrows 95. The bales promote uniformity of consistency of slurry at every point across the width of the belt 26, since there is constant right and left mixing as the liquid-solid suspension moves down through the series of successive diamondshaped pockets 96. Thus, pocket 96 receives some liquid from three upstream pockets 97, 98, and 99, mixes them, and discharges at its downstream corner 100 into three downstream pockets 101, 102, and 103 (the latter being partly broken by the overlap attachment section 91). The current tends to carry along most of the particles in the downstream corner 100 of the pocket 96. The upstream sides of the bales are swept fairly clean of any deposit. However, the heavier particles of valuable metal tend to accumulate at the downstream sides of the bafies and particularly in the upstream corner and the right and left corners of the pockets, such as pocket 96. The downstream sides of the bafes slightly overhang the bottoms of the pockets, a feature which encourages the accumulation of metal particles. However, it will be seen that the oblique arrangement of the batlles 88 and 89 insures that even the deposited concentrate will be constantly subjected to some washing, whereas in ordinary Y transverse bales, a deposit is likely to remain even if of lower density than desirable concentrate. In the present invention, however, a concentrate which has not arrived at the maximum density, which indicates the desired degree of separation, will be washed away by the relatively heavy current of water at the upstream end of the ore concentrator 10. It is only that deposit which is suitably dense which will be able to resist the transverse currents eddying about the downstream wall surfaces of the bales 88 and 89.

It will be understood that the degree of inclination, dimensions, and the rate at which water is passed down the incline of the ore concentrator will be determined by such factors as the material being treated, the neness of the particle size, and the eciency of separation which is desired to achieve. In general, however, ores must be granulated to a size not larger than l mesh. Most ores are suitably passed over an incline of between 10% and grade. The volume of water and slurry admitted should be sufficient to maintain a ow not much deeper than the bales themselves, which must be of sucient depth to shield accumulated metal particles from being washed away Ytoo readily, i. e. about one eighth inch to one inch in depth for the preferred range of ore pulverization and wet-ore concentrator construction.

It will be appreciated that the specific embodiment shown might be varied in details without departing from the principles of our invention, and that our invention is not restricted to the form described but rather by the scope of the appended claim.

We claim:

A wet-ore concentrator of the typerin which a stream of finely divided ore slurried with water is flowed down over an inclined surface, which includes: a plurality of inclined sluice channels; a slurry hopper disposed transversely across said sluice channels at a point intermediate their upstream and downstream ends; means for introducing finely divided ore and water into said slurry hopper; agitation means in the lower portion of said slurry hopper for intimately mixing said finely divided ore and said water; walls in the bottom of said slurry hopper defining a slurry distributor having a plurality of openings for distributing slurry from each part of said hopper to one of said sluice channels; a flexible endless belt of rubber-like material mounted in each of said sluice channels and adapted to be moved upstream in said sluice channel and to return under said sluice channel from the upstream end thereof to the downstream end; side walls on each lateral edge of each of said belts, said walls formed integrally with said belt material and adapted to conne a downowing stream therein; a series of right ow bales molded integrally in the surface of said belt and disposed obliquely across the path of said downowing stream with their right ends downstream from their left ends so as to impart a right transverse component to the flow of said stream; a series of left ow baflles molded integrally in the surface of said belt and disposed obliquely across the path of said downowing stream, with their left ends downstream from their right ends so as to impart a left transverse component to ow of said stream, said left flow bales intersecting said right ow batles to form diamond-shaped pockets on the surface of said belt; and adjustable water supply means at the upstream end of each of said channels for introducing additional water as required by the slurry supplied Vto said belt therein from the particular part of said slurry hopper with which it is in communication; and means under said inclined chanels for collecting heavy particles from said belts.

References Cited in the le of this patent UNITED STATES PATENTS 111,713 Young Feb. 7, 1871 486,622 Tulloch Nov. 22, 1892 489,744 `lohnson Jan. 10, 1893 994,439 Brooks `Tune 6, 1911 1,030,427 Pinder June 25, 1912 2,103,663 Curtis Dec. 28, 1937 

